Misfire no code.. dear Ford die in a fire

[lamrith]

Some car just have issues.  I don't blame you for wanting to dump it, I did that with my car before this and it never had major breakdowns like you are seeing.  Your severe rash of issues is not normal, get out from under her and get a 13+ and never look back man.

[lamrith]

Do you have a scanner with the ability to monitor misfires? Are you absolutely sure it's not drive train related?  If it truly is misfiring, whether it throws a code or not, there should be data at that rpm that you can look at that can point you in a direction or a specific cylinder.  If it's misfiring there's a huge difference in things to look at between multiple randoms vs a specific cylinder.

Good point.  I know our resident tuner has the ability (at least 13+) to check for knock by cylinder.  may or may not be able to do for misfire?

[shoNoff]

Some car just have issues.  I don't blame you for wanting to dump it, I did that with my car before this and it never had major breakdowns like you are seeing.  Your severe rash of issues is not normal, get out from under her and get a 13+ and never look back man.

13+ owner here with a constant list of problems at 72k miles. It's one thing after another for the last 25k plus. I think you just either get a good one or a bad one. And topher and I got bad ones.

[TopherSho]

Do you have a scanner with the ability to monitor misfires? Are you absolutely sure it's not drive train related?  If it truly is misfiring, whether it throws a code or not, there should be data at that rpm that you can look at that can point you in a direction or a specific cylinder.  If it's misfiring there's a huge difference in things to look at between multiple randoms vs a specific cylinder.

on the misfire :  the SCT handheld shows a big fat zero.  Someone mentioned that i need a different reader than the SCT to catch them on the fly.

as to how sure :  #$%ING sure.  pull over, you can hear the missfire on one cylinder. and the log shows a rpm jitter at 61 seconds + that is ''classic'' misfire behavior that i saw the LAST TIME i had misfire issues.  (attached log)



Hey are BOSCH injectors OEM

[TopherSho]

So i have narrowed the behavior down (i think).

under manual mode @>3000 rpm with *NO LOAD* one cylinder is unable to burn all the fuel, and as long as there is no load or negative load (Decel hard foot off gas in gear 2) it continues the behavior until the spark plug wont fire

also important to note the AFR seems normal. 

then i get the flashing cel with no code for the SCT,  and i feel it misfiring on only 1 cylnder.  after about 20 seconds of idle in park or tun engine off cylinder no longer wet all ok..

if you are accelerating moderately or hard it **seems to not occur** ... but i am deathly afraid to try to force the issue to occur under high load

my only conclusion is the sp542 plugs are still not good enough for me to run at .028 gap and or are too cold.  will replace them later with one heat rang up,  and close the gap **slightly** to .029

for now im going to drive it in normal drive mode for another 5000 miles and revisit the issue.   the whole setup is under 3500 miles on a new engine,injectors,plugs so thee may be a wear in issue still working itself out.

[76fomoco]

FWIW I have received brand new factory plugs that were bad right out of the box.  also worth checking the boot inside for damage to the connection point to the plug.